Certain operations of electronic circuit board assembly involve supplying micro devices by a micro device feeder to a robotic handling system. The micro devices include a broad range of electronic and mechanical devices, such as programmable devices. Examples of programmable devices include, but are not limited to, devices such as Flash memories (Flash), electrically erasable programmable read only memories (E2PROM), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), and microcontrollers.
The micro device feeders are generally aligned and connected underneath the robotic handling system. The micro devices are typically supplied in tape on reel. The tape includes a plurality of pockets for containing the micro devices. Typically, there is one pocket across the width of the tape. The tape has sprocket holes or perforations in one side so that it can be driven through the micro device feeder.
The micro device feeder has a frame upon which a motor and pulley arrangement is mounted to drive a sprocket, which engages the perforations to linearly drive the tape through the micro device feeder. The frame also carries a spring-loaded backup plate to support the tape and also accommodate any sudden variations in tension in the tape.
The robotic handling system removes the micro devices as the micro device feeder in the tape linearly presents them and places them on buffer areas of the micro device feeder or directly on printed circuit boards moving through an electronic assembly line or manufacturing system. In high-speed systems, the robotic handling systems may include linearly moving pick-and-place mechanisms. In such a system, the centerline of the linearly moving pick-and-place mechanism typically coincides with the centerline of the pockets in the linearly moving tape.
One problem associated with the handling of micro devices carried on tapes is that different micro device feeders are usually needed for different sizes of micro devices because different sizes of micro devices are typically supplied in different sizes of tapes. For example, three different micro device feeders are typically required for 16-, 24-, and 32-millimeter wide tape. The reason for requiring a different micro device feeder is that the centerline of the linearly moving pick-and-place mechanism doesn't typically coincide with the centerline of the pockets in the linearly moving tape for different tape widths because of the perforations in the side of the tape.
The perforations in the tape typically cause a different offset between the centerline of the pockets and the centerline of the tape for each different tape width. Since the frame is connected to the robotic handling system, the motor and pulley arrangement, and the sprocket, the centerline of the linearly moving pick-and-place mechanism is fixed relative to the centerline of the sprocket. The centerline of the sprocket fixes the centerline of the perforations, which means that the offset may cause the centerline of the pick-and-place mechanism to not coincide with the centerline of the pockets.
A typical company may handle different size micro devices supplied in tapes with different size tape widths, and thus require a large number of different size micro device feeders, which may be both inconvenient and expensive.
Different approaches have been taken to try to solve this problem. One approach involves using a tape module, which forms a portion of the micro device feeder. The tape module is replaced for supplying micro devices contained in tapes with different widths. Therefore, instead of replacing the entire micro device feeder to accommodate for different size tape, only the corresponding tape module needs to be replaced. However, the tape module may constitute almost half of the mechanism of a micro device feeder, so it is still inconvenient and expensive to stock large number of tape modules to handle different size tapes.